Cacophonic Shield(Spell Compendium, p. 41)
Level: Bard 4, Sorcerer 5, Wizard 5,
Components: V, S,
Casting Time: 1 standard action
Range: 10 ft.
Area: 10-ft.-radius emanation centered on you
Duration: 1 minute/level (D)
Saving Throw: Fortitude partial
Spell Resistance: Yes
Your words speed into a jumble of sounds that mix together until only a constant, faint buzzing sound remains.
You create a barrier of sonic energy at a distance of 10 feet from yourself. Creatures on either side of the barrier hear it as a loud but harmless buzzing. Nonmagical sound (including sound produced by a thunderstone) does not cross the barrier. Supernatural or spell-based sounds or sonic effects penetrate the barrier only if the caster or originator of the effect succeeds on a caster level check (DC 11 + your caster level).
A creature that crosses the barrier takes 1d6 points of sonic damage +1 point per caster level (maximum +20) and must make a Fortitude save or be deafened for 1 minute. The sonic vibrations create a 20% miss chance for any missiles (including siege weapon attacks) crossing the barrier in either direction. The barrier moves with you, but you cannot force another creature to pass through it (for example, by moving adjacent to an enemy). If you force a creature to pass through, the barrier has no effect on that creature.